SRC Attribute

Src binding handler is a shorthand for elements which require
src
attribute to be dynamically updated.
This binding should be used with elements supporting src
attribute like images and iframes,
img and iframe tags respectively.
The src binding handler itself is not limited to
images and iframes however, the binding will add src
attribute if element does not have one.

Elements having src attribute

audio - the URL of the audio file

embed - the address of the external file to embed

iframe - the address of the document to embed in the iframe tag

img - the URL of an image

input - the URL of the image to use as a submit button (only for type="image")

script - the URL of an external script file

source - Required when source tag is used in audio and video tags. Specifies the URL of the media file

track - the URL of the track file containing subtitles or caption for video or audio tags

video - the URL of the video file

Live example

In this example with binding is used, making HTML code even more clean.

Filename:

Image with src binding:
Image with src punches:

While it is possible to use knockout punches for src
attribute it is highly not recommended as browser will
request resource named as binding value -
in this example: {{filename}} -
before bindings evaluation.